Budgerigar breeders allow their birds to reproduce at varying times of the year. Although there are those that practice continuous breeding, most will have defined breeding seasons. The timing of this season will be determined by a number of factors such as the climate in their part of the country, whether the birdroom is air conditioned and the use of the Spring environment for those people with outside aviaries. For fanciers who breed and show the exhibition Budgerigar the duration of the breeding season is considered to be November/December through to May/June each year. The two factors, neither of which have any scientific foundation, which account for this are the date on which the closed bands are issued and the timing of the show season.
In the USA, breeder bands are issued by the American Budgerigar Society for the start of the year and so consequently there is an attempt to have young birds in the nest for this date. The show season runs from June until November and it is desirable to have current year babies as mature as possible for these shows. In addition, so that adult stock can also be exhibited, they need to have finished their time in the breeding cage and had time to recover. While these points are a valid explanation for breeders actions in terms of breeding season timing, it may also account for some of the problems that are encountered each year, specifically with regards to infertility and seasonal setbacks. In recognition of this it may be highly profitable to consider some of the scientific data that is available on many aspects of Budgerigar breeding.
Seasonal And Continuous Breeders
Among the bird populations of the World there is a division between "seasonal breeders" and "continuous breeders". It has been a long held belief that Budgerigars are continuous breeders whose reproductive urges are under constant stimulation, except when unfavourable environmental, maturity or health condition prevail. This now appear to be untrue, as research shows that in the wild Budgerigar there are definite breeding cycles. This can be confirmed by the facts in these wild flocks, breeding occurs in the Spring in the far South of Australia, an area which enjoys are very temperate climate, and in the tropical North it is during the winter. However, in central Australia, breeding takes place in spring, summer and autumn but not in winter. Also, research has discovered that in the domesticated cock Budgerigar there are four definite periods of sperm production each year, with the consequential near barren periods in between. It can be concluded that these cycles of sperm production are also true of the wild bird.
In addition to the non-production of sperm, there are a number of other changes in appearance of the mature cock bird that include cere colour, plumage changes, song etc., which may be related to breeding or non-breeding condition. During the non-breeding phase for instance, the birds will moult and their ceres become less intense in colour. Conversely, during the fertile period the ceres are bright in colour. This would indicate that during the non-breeding periods the hormone "testosterone", which is responsible for a variety of secondary sex characteristics, has either considerably diminished or ceased in its production. In seasonal breeders, which Budgerigars appear to be, the production of the hormones that cause breeding condition are constantly in a state of inhibition. To free this, certain exterior factors, known as "release factors", come into play.
Environmental Stimulation
Photoperiodism
Photoperiodism is the effect that the length of day has on the desire to reproduce. In some species of bird the length of day plays a great part in their reproductive cycle, however, for many periodic breeders, such as Budgerigars, this stimulation is not highly effective. In support of this, over a number of years a series of studies have been carried out in the attempt to ascertain exactly what effects daylight has on the Budgerigar. Three of these are quite notable but turn out to have contradictory results. These can be summarised as follows:-
Vaugien, 1953
One group of fledgling Budgerigars were exposed to natural daylight conditions and another to continuous light. At day 84 the cock Budgerigars that had been exposed to the continuous light showed very little testicular development and their sperm production was non-existent. However, those birds subjected to the natural light had large sperm producing testes. Vaugien carried out further experiments to confirm this.
Van Tienhoven, 1966
A comparison with the effect of natural daylight and a 14 hour light/10 hour darkness regime was set up. This concluded that hens kept in the natural light environment all produced eggs, while only 1 in 12 from the other group actually laid.
There were however, differences between the two experiments as Vaugien housed only cock birds while Van Tienhoven had both sexes and these could also hear other birds. Nest boxes were also present.
Putman and Hinde, 1973
These experimenters found no difference in egg laying between the effects of natural daylight compared to 2 hours of light and 22 hours of darkness and also 6 hours of light and 18 hours of darkness. These birds were housed in a cage with the nest box in position and the sound of male birds.
It can be seen that from the results of these experiments that they were inconclusive, other than to indicate that the effects of light do not play a major part in the Budgerigars reproductive patterns. However, a conclusion can be reached.
Vocalisation
From these trials, as well as others, it became apparent that for the female, hearing the call of the male is more important than the effects that light may have on her breeding condition. Researcher Brockway in 1969 demonstrated that "male courtship vocalisations can induce ovarian development in female Budgerigars under short daylight conditions, without access to a nest box." Earlier, in around 1960, another investigator by the name of Ficken, concluded that pairs of Budgerigars isolated from other pairs rarely showed interest in a nest box but as soon as the sounds of other pairs were exposed to them, the nest box became the focus of attention. Finally, in 1960, Brockway further demonstrated that males that were played the sounds of other males producing a loud warbling call also made similar calls, there was testicular development and sperm was produced. This same sound produces nesting behaviour in hens but it was the soft warble of the cock bird that was necessary for the stimulation of egg production.
So we can conclude that the sounds that the Budgerigar makes play a very important roll in their breeding results but this is not the end of it. There are other essential stimulants.
The Nest Box
It would appear that the presence of a nest box is equally important for the hen to commence her internal development which will lead to egg laying. In the first few days, it is the song of the cock bird that encourages nest box behaviour in the hen. After entering the nest box, the egg follicles on her ovaries start to enlarge and there is an increase in weight in the oviduct. Albumen begins to form ready to be collected by the egg as it travels along the oviduct and the feathers on the bird’s brood patch are discarded. These events do not occur until after the hen has been intensely occupied with the nest box for 3 or 4 days. Once begun, the sequential process of egg laying will continue automatically without further external stimulation, after the sixth day prior to egg laying has been passed.
The first egg is usually laid after the eighteenth day of pairing and the rest follow at two day intervals. There are two types of egg layers in birds, those referred to as "determinate" layers and those as "indeterminate" layers. Determinate layers, the group in which Budgerigars fall, have a set number of eggs in a clutch based on the number of egg follicles that mature on the ovaries at the commencement of laying preparation. These numbers may vary in each clutch from 4 to 12 but lost, damaged or removed eggs cannot be replaced. However, there is a way in which a Budgerigar hen may be "milked" and that is to remove and foster her eggs as they are laid. By doing this it triggers the next egg laying cycle and consequently as one round finishes the next starts almost simultaneously, giving the impression that she is an indeterminate layer. Supreme examples of indeterminate layers are game birds and fowl, which will lay continually if their eggs are collected daily.
Relative Darkness
In studies carried out by Hinde and Putman in 1973, where they investigated the effects of the nest box and light on egg production, it was found that one of the features of the nest box that is important in inducing eggs laying, was the relative darkness that the box provides. Also, in 1962 Brockway demonstrated that the position of the hole in the nest box in respect to the perch location is of crucial importance to nest box entry. Females did not demonstrate early nest box oriented behaviour when the perch was 2 inches above or below the hole but did show immediate exploration of the box when it was placed 6 inches below the hole.
Once the hen has entered the nest box her actions are aimed at the external cage environment, such as looking out through the nest box hole and preening, and gnawing or standing in the nest hollow. As egg laying approaches so her nest hollow activities increase and once the first egg is laid, 90% of her time is spent in incubation. Where nest boxes were provided with a soft pulped paper nest bottom rather than a wooden concave, hens showed two to three times more gnawing activity. This gnawing peaked at four to six days prior to egg laying but never occupied more than 30% of the time spent in the box. It was concluded however, that this gnawing activity is not essential to ovarian development and does not affect the duration before the first egg is laid.
The cock bird will enter the nest box at an average of six days prior to the first egg being laid. They do not participate in the nesting behaviour of the hen, nor do they play any part in incubation of the eggs. Male nest box conduct initially centres on preening both himself and his mate, plus displays of courtship and feeding of the hen. Following the first egg being laid, the cock may position himself parallel to the hen on the edge of the nest box hollow.
Mate Selection and Pair Bonding
There are two areas of interest under the heading of mate selection and pair bonding and these concern the behaviour of the birds that determine they are a bonded pair and how the bond occurs. This information is very important to the approach to the pairing of our own birds and can assist us in improving our breeding results. The first thing to consider is the fact that bonds made outside of the breeding season, in the flock, will remain intact throughout the year. In terms of mate specific behaviour (ref. Trilmich 1976), this can be identified as:-
From the above it can be concluded that both partners can recognise their own mate.
In supporting research it has been shown that when it comes to mate selection, it is the hen who ultimately makes the final choice of partner. It has also been shown that, given the choice, selection of a mate by the hen is based on three factors:-
The hen however, cannot tell the difference between the voice of two courting males.
It was also discovered that the "pair bond" takes place on the first day of the cock and hen meeting and will remain intact so long as the pair are together. However, if they are separated for 4 to 5 days, the bond will be broken.
Practical Pairing
Armed with this knowledge concerning bonded pairs of Budgerigars, we can use it to our benefit. For many years breeders of exhibition Budgerigars who wished to select specific mates themselves, used to fly their birds with the sexes kept separate. The theory was that pair bonds would not develop and breeding results would be enhanced as a result. In reality, what happened was without the presence of cocks to keep them active and interested, the hens became fat and lazy and their performance in the breeding cage suffered as a consequence. As for the cock birds, they gained no sexual experience of the opposite sex during their early development. This also affected their libido and ability to mate. In addition, breeding condition was not always achieved simultaneously across the sexes as it would be in a mixed group. It was common to hear breeders say, "My cock birds are fit and ready to breed but my hens are in a moult." or vice versa.
Today we always keep our Budgerigars in mixed groups for the main part of the year. As I said to a group of Australian fanciers, who still keep their birds segregated, on a visit to Adelaide recently, "If you can take me out into the bush and show me a cock tree and a hen tree I will agree with you but until then, the most natural way for Budgerigars to live is in a mixed flock." It has been suggested that in the wild, just prior to commencing to breed, the hens leave the flock on their own and proceed to the nesting grounds ahead of the cocks. Whether or not this is true, my pairing technique allows for this and at the same time breaks any bonds that may have occurred in the flight.
The Technique
Prior to the start of my breeding season, which is usually at the end of November each year, I prepare the breeding room by cleaning the cages and nest boxes and generally making ready. I have already selected my breeding pairs based on a strategy for quality improvement and variety production. The hens that are to be a part of the breeding team are caught up and placed into their respective breeding cage. Nest boxes are in position and each contain a good handful of wood chippings. As we have already discovered, the gnawing action of the hen does not affect her ability to lay eggs but I prefer them to gnaw on the chippings. that I provide rather than an expensive nest box. Many hens will eject all of the chippings as if they were cleaning out last years nesting hollows but at the very least they get the opportunity to customise, what is to be their homes for the next few months. Once the hens are installed any spare hens are also caught up and placed in stock cages leaving just cock birds in the flights. I usually do this on a Tuesday evening.
Cock birds are at their most active first thing in the morning and so these are introduced to their selected mates on the following Sunday morning. With the lapse of 4 days any pair bonds will have been broken and it is most unusual to have rejections. When the cock is introduced, because the hen had become confident in her surroundings she will be pleased to meet him and select him as her mate and she will often stand immediately for mating. As for the cock bird, he can’t believe his luck and readily accepts his chosen partner. Although mating may be seen to take place this still does not guarantee full eggs as the cock could be at the low ebb of his fertility cycle. Equally, there will be many pairs that will you never actually see mate, although clearly they must at some time, but still full eggs are produced.
The Effects Of Rainfall
It can be concluded that distinct recognition and an enduring pair bond are two factors that favour the individuals learning to predict a partners reaction and readiness to act, so as to adjust their own actions accordingly. Also, supporting this is the notion that permanent cohesion of the pairs inside the flock, outside of the breeding season, has probably developed by selective pressures because of the unpredictability of rainfall, which in turn produces favourable breeding conditions. When rainfall does occur, permanently bonded pairs can start breeding immediately and it has been concluded that there is a link between breeding in the wild and rainfall.
It was first thought that as Budgerigars do not require drinking water and use metabolic water, they may have needed drinking water for reproduction. However, research by Wyndham in 1980 demonstrated that even without water, Budgerigars in a dry climate area of Australia, still had testicular activity and produced sperm. Further research was carried out to discover that Budgerigars go to nest 3 to 5 weeks after rainfall and this was concluded to be as a direct result of future food supplies.
Due to the natural cycle of Budgerigars, giving them periods of sexual inactivity, but also being quick to respond to external stimuli, this would account for the 3 to 5 weeks delay after rain before nesting takes place. Unfortunately, we still do not know what it is about the rainfall that affects Budgerigars but we can be relatively sure that it is not the need for drinking water that is the sexual stimulant. Whatever the cause, which could be brought about by visual, audible or tactile effects, rainfall does stimulate hormone release. In say this, we also know quite positively that Budgerigars breed well in captivity without exposure to either sight, hearing or the feel of rainfall. Finally, an unexplored avenue is the effect of barometric pressure on hormonal stimulation.
Physical Activity
n his study, The Effects Of Exercise On Reproduction In Budgerigars, Kenneth R Welle addressed the statement, "Budgerigars need to fly if they are to get their needed exercise and be in condition to breed". Although the basis of the experiments carried out left much to be desired, it was concluded that exercised groups as a whole had a much higher hatching rate and substantially improved total weight of young produced than non-exercised groups. In a later experiment it was shown that Budgerigars confined to a breeding cage measuring 16" x 13" x 8" showed only a 40% hatching rate whereas the groups allowed free flight prior to and during the breeding cycle had a 90% hatching rate.
Some families of Budgerigars, like people, put on weight far more easily than others. As we have already discussed, housing mixed groups of the sexes together keeps activity as its highest and consequently the exercise rate is high. Whether you keep your birds flighted or caged there is little disputing the fact that fat Budgerigars will not reproduce successfully. Both sexes will suffer from a poor sex drive, mating will be difficult, strain on the heart could be fatal and egg binding amongst fat hens is not uncommon.
Bird Room Environment
Many breeders appear to be obsessed with the idea that an increased humidity level in the breeding room will improve chick production rates. Experiments carried out at the University of Liverpool in England proved that the environment under sitting hens is ideal for hatchability and developing chicks and is almost entirely unaffected by the surrounding air. Modifying the birdroom temperature and humidity will have no effect on the environment under the hen as she will make any necessary adjustments herself. Also, if the breeder introduces moisture directly into the nesting area this can prove to be detrimental as eggs may chill following evaporation of the water, and moisture is a medium for bacterial growth.
In the wild, small amounts of wood chippings are found in the nest hollows of Budgerigars and as already explained, I also placed wood chippings into my bird’s nest boxes. If these are used directly from a sealed container they can in fact have a drying effect on the atmosphere in the nest box, which in turn can affect the developing eggs and chicks. To minimise this, any wood chippings that are to be used within nest boxes should be left to breath in exposed air for a week before use.
We continue our study with perhaps a subject that is very much taken for granted by the majority of Budgerigar breeders but one, if overlooked, can have serious consequences on the overall success not only in the breeding season but during the rest of the year as well.
Nutrition
Although a great deal is continually written on the subject of Budgerigar nutrition based on both fact and opinion, there is no doubt that diet does affect egg laying, hatching and the viability of the resulting young. The important aspect is that different items react with each other and may inhibit or be needed as a catalyst.
As an example of this, we provide our birds with cuttle fish bone, shell or grit and milk on softfood. Each of these contain Calcium, yet Calcium deficiency is one of the most common mineral deficiencies found in cage birds today. There are two major reasons for this. The first concerns the feeding of tonic seed mixes that contain a high level of oil seeds. The fats in these seeds combine with the available Calcium intake in the gut and then form substances known as insoluble soaps. These cannot be absorbed and wash straight through the bird, Calcium and all. The second of these is brought about from indoor aviaries. Many breeders keep their Budgerigars in the basement, spare room or garage and they never become exposed to the outdoors. The only way in which living creatures can manufacture Vitamin D is through exposure to sunshine. Vitamin D is essential for Calcium absorption. The eventual Calcium deficiency leads directly to a reduction in the number of eggs being laid.
If your birds lay soft shelled eggs then nutritional deficiencies should be suspected and Calcium plus Vitamins A and D need to be supplemented. Vitamin A is the most commonly deficient vitamin in cage birds and this leads to decreased hatchability and high chick mortality. It’s deficiency has also been linked to reproductive disease. Vitamin D, as mentioned, is required for intestinal absorption of Calcium used in bone structure and egg shell. Improvements in bone synthesis appear to be directly related to an increase in the conversion of Vitamin D to active Calcium absorption through the influence of supplemented Vitamin C in the diet. Also, a possible reduction in early mortality in chicks can be achieved through supplemental Vitamin C during the first 4 weeks of life.
Other Deficiencies
In addition to Calcium, other mineral deficiencies are common in Budgerigars. These include Zinc, the absence of which produces slow growth and reduced egg hatchability; Manganese, which reduces egg production, decreases hatchability and produces thin shelled eggs. On the other hand, due to all seed diets Phosphorous can affect the ratio between Calcium, Vitamin D and Phosphorus. The correct ratio of these substances is essential in maintaining normal skeletal metabolic and reproductive functions.
In a survey of diseases causing death in Budgerigars, it was found that a very high incidence of thyroid hyperplasis (goitre), due to deficiency in Iodine existed. Iodine deficiency stops the production of the hormone Thyroxin which is essential for good breeding results.
Deficiencies in Pantothenic Acid in adult birds causes reduced hatchability, as does deficient Folic Acid. It is also important to note that Niacin in cereal grains such as oats, corn and Soya bean cannot be utilised by birds. Deficiencies in these B Vitamins result in poor egg production and poor hatchability. Again in adult birds, Biotin deficiency will result in normal egg production but reduced hatching.
As with Vitamin and Mineral deficiency, protein deficiency as in Amino Acids has a dramatic effect on reproduction success. Severe shortage will result in the re-absorption of the ova and termination of egg laying.
So there we have it. Hopefully this article will serve it’s purpose by helping Budgerigars breeders understand some of the otherwise overlooked aspects of their management that can and will affect the breeding season. It is hoped that you are now sufficiently stimulated to try and incorporate some of these factors into your regime in an attempt to improve breeding results.
In closing I would like to thank James Bratt from Florida whose contributory material made this article possible.